I know how I approach working up a load for my rifles and I have always been somewhat "consertive" as I approach the listed MAX loades listed for what ever I am loading. I have on occassion gone slightly over the listed MAX.

Now assuming for this discussion that you accuaracy was slightly improving or remaining stable as the powder charge was increased, what "signs" or method do you use or rely on to tell you when to stop. Do you go until you see something or sense something or???????

Sensitive issue!

I don�t think there is any reliable methods of detecting pressure without a some sort of device, like the Oehler system wich detects/measures levels of pressure. I do not have any pressure measuring device, the are expensive, so I rely on "feel" and indicators like primer flattening and measuring casehead expansion. What I do first when usin a new load is to try and detect if the spent case extracts aqs easy as a factory load, if you have a bolt rifle then bolt lift should be as easy as with factory loads. Then I check the case for primer flattening, I always use Rem. 9 1/2 primers so I know what they look like in my rifle when the pressure is high. You may not get any indications this way in your rifle and with the primers you use, but it works for me. There are several reloading manuals that show pictures of cases with different levels of primer flattening, so you can get an idea of what to look for.

Then I check the case for any shiny marks on the base indicating that brass has flowed into the ejector pin hole. A shiny mark means to high pressure.

When I get home from the shooting range I measure case head expansion with a micrometer and compare it to an unfired case. I compare the expansion with that of a factory load, to keep it safe.

If, after a while, your primer pockets become loose your load is too hot for the brass and /or the rifle you are using.

Using the pressure indicators above I have kept my loads safe and reliable, but I would add that I never go above max. as indicated in the reloading manuals I use, but I do "shop around" between manuals to find the "maximum maximum"....

Most guys with guns stronger than the brass increase until the case head increases so they can measure it with a micrometer, then they back off a safety margin.
This is sometimes called the "Ken Waters method".

Personally, I increase until the primer gives up, the primer pocket gives up, or the bolt gets sticky.
Then I back off a safety margin.

I have really tried to blow up alot of guns.
I have never been able to dammage at all a 98 Mauser or 91/30 Moisin Nagant bolt actions in work ups to the sticky bolt.
I have blown up 4 revolvers and 2 CZ52 pistols into little pieces.
I have caused minor dammage to some other pistol designs.